text: #pragma once
  
  #include "i_node.h"
  #include "i_operation.h"
  
  class OperatorNode : public INode {
    IOperation* operation_;
  
   public:
    explicit OperatorNode(IOperation* operation);
    void Act(std::stack<double>& s) const override;
    virtual ~OperatorNode();
  };
  